“UV Crosslinkable Styrenic Block Copolymers . . . A Door to High Temperature Heat Resistant Hot Melt Adhesive Applications” by Martine Dupont, the Journal of the Adhesive and Sealent Council, Inc., 1997 Spring Convention, Pittsburgh, Pa., Mar. 23-26, 1997, pp 229-240, discloses compositions containing 25 to 35 wt-% of a block copolymer KX-222C, a solid hydrogenated tackifying resin Regalite R91 or MBG 264, a hydrogenated liquid resin Regalrez 1018, a photoinitiator Irgacure 651 and an antioxidant Irganox 1010. The composition exhibits the lowest viscosity of 10 Pa.s at 160° C.
U.S. Pat. No. 5,804,663 discloses radiation sensitive vinyl aromatic block copolymers and radiation curable adhesives, sealants, and coatings containing such block copolymers. The radiation sensitive block copolymers contain at least one block derived from vinyl aromatic monomer and at least one block derived from butadiene. The adhesive exhibits the lowest viscosity of 6.7 Pa.s at 160° C.